The present invention relates to drums, and more particularly to drums whose pitch is adjustable by rotation of the drum shell and/or activation of a pedal connected to drumhead-tensioning apparatus.
It is well known in the art to adjust the pitch of a drum by varying the tension on the drumhead. Devices for achieving this function have typically been used in conjunction with tympani, and have consisted of assemblies whereby activation of a pedal stretches the drumhead to increase the pitch. Tympani are also known which are adjustable in pitch by rotation of the drum shell about a central support axis. While combined pitch adjustability by rotation as well as by a pedal arrangement has been found in the prior art, the pedal-adjustable feature of such drums has typically required a large, heavy, cumbersome apparatus which is not separable from the drum itself.
Another type of drum whose pitch may be varied by rotation is a drum which has been manufactured and sold for a number of years by the assignee of the present application under the trademark "RotoTom". A "RotoTom" drum has a drumhead stretched over an upper die casting or "spider" and held by a counter hoop. The upper die casting has a central hub against whose lower surface abuts a threaded shaft. Threaded upon the threaded shaft is a lower die casting or spider rigidly affixed to the counter hoop. Rotation of the lower die casting about the threaded shaft causes the force exerted on the drumhead by the upper die casting to vary, thus changing the pitch of the RotoTom drum.
No means has yet been made available for adjusting the pitch of a "RotoTom" drum by means of a pedal. Thus, it has heretofore been required to use at least one hand to change the pitch of a "RotoTom" drum, so that a drummer was not free to play the instrument with both hands while performing a pitch adjustment.